What Are The Maintenance Methods For Low-voltage Distribution Cabinets?

The maintenance of low-voltage power distribution cabinets is mainly to ensure the normal and safe operation of low-voltage power distribution cabinets. The low-voltage power distribution cabinet should be inspected and maintained annually. The maintenance is completed with the least power outage time, and the owner's power outage time is generally determined in advance.

Contents and steps of maintenance of low-voltage power distribution cabinets:

1. The maintenance should start from the low-voltage side of the transformer. After the power distribution cabinet is powered off, clean the dust in the cabinet, check whether the busbar and down-conductor are well connected, whether the joints are heated and discolored, check whether the cable head and the wiring pile head are firm and reliable, check whether the ground wire is corroded, and whether the wiring pile head is rusted. Is it tight. All secondary circuit wiring connections are reliable, and the insulation meets the requirements.

2. When checking the drawer switch, the drawer switch cabinet should be flexible when pushed in or pulled out, and the mechanical locking is reliable. Check whether the automatic air switch operating mechanism on the drawer cabinet is in place and whether the wiring screws are tightened. Remove the dirt on the contact surface and surrounding area of the contactor, and check whether the contact of the contactor is in good condition. 1/3 of the thickness), the contacts should be replaced. The power indicator and indicator lights are in good condition.

3. When overhauling the capacitor cabinet, the main switch of the capacitor cabinet should be disconnected first, and the capacitors should be discharged to the ground one by one with a wire of more than 10mm2. Deal with it in time and replace the discharge device, the wiring screws of the control circuit and the grounding device. After closing, debug the indicating part and the automatic compensation part.

4. Overhaul of circuit breakers in the power receiving cabinet and liaison cabinet: After disconnecting all loads, use the handle to shake out the circuit breaker. Re-tighten the terminal screws and check whether the elasticity of the blade meets the requirements. Check whether the arc chute is broken or damaged, check whether the opening and closing of the mechanical interlock is accurate, check whether the contacts are in good contact, repair and file the surface of the contacts if necessary, and check whether the internal springs, gaskets, and screws are loose, deformed and fall off. .

Overhaul of the substation:

1. Before operation, the following steps should be followed: disconnect the load on the low-voltage side one by one, disconnect the circuit breaker on the high-voltage side, turn on the grounding switch, lock the high-voltage switchgear, and hang a "prohibit closing" on the handle of the switchgear. , someone working" sign, and then use a wire of 10mm2 or more to short the busbar and hang the ground wire, and fasten the busbar screws.

2. Maintenance operation steps: re-clean the contacts of the busbars, apply power compound grease, fasten them with new spring washer screws, check whether the insulators between the busbars and the space connections are abnormal, check the current, voltage, etc. The reliability of the connection of the secondary winding terminals of the transformer.

3. Inspection and test before power transmission: remove all grounding wires and short-circuit wires, check whether there are tools left at the work site, and after confirming that they are correct, close the isolating switch, disconnect the grounding switch on the high-voltage side, close the circuit breaker on the high-voltage side of the operating transformer, and take the Put down the sign, send power to the transformer, then close the circuit breaker of the low-voltage side power receiving cabinet, send power to the busbar, and finally close the relevant liaison cabinet and the automatic air switch of each branch.

Precautions:

1. During the maintenance process, a special person must be set up to monitor.

2. Electricity must be checked before work.

3. Maintenance personnel should be familiar with and operate the electrical and mechanical interlocking of the entire power distribution cabinet.

4. During the maintenance, you should know in detail which lines are two-wire power supply.

5. When overhauling the busbar, the residual charge in the line should be fully discharged.